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SVN::Utils::ClientIP 0.01
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NAME
SVN::Utils::ClientIP - Get the client's IP address in a Subversion Hook
SYNOPSIS
use SVN::Utils::ClientIP qw(ssh_client_ip);
print "The client's IP address is ", ssh_client_ip();
DESCRIPTION
SVN::Utils::ClientIP solves the age-old problem of obtaining the SSH
client's IP address in a commit hook of a Subversion repository.
Knowing the client's IP address can be quite useful in heavily used
Subversion installations, as it allows for maintaining a log on who
accessed a repository when and from where.
However, the Subversion developers are not very accomodating when it
comes to this, claiming "security purposes":
http://svn.haxx.se/users/archive-2009-02/0804.shtml
But, if you think about how a client connects to the repository using
SSH, which then spawns the svn process, it becomes quite clear how you
can get the IP address, even if the Subversion folks are hiding it from
you: Starting from the currently running hook, walk up the process
hierarchy, until you reach the parent that's the SSH instance serving
the client (only tested with openssh). In its environment, you'll find a
variable named SSH_CLIENT, which contains the IP address of the
connecting client.
This is exactly what this module does, and you can simply obtain the SSH
client's IP address by running
use SVN::Utils::ClientIP qw(ssh_client_ip);
my $ip = ssh_client_ip();
Under the hood, the module uses the CPAN modules Proc::ProcessTable for
obtaining the ppid() to walk up the process hierarchy and
Proc::Info::Environment for reading out the SSH_CLIENT environment
variable. By the time of this writing, the latter only worked for Linux,
but in the meantime other OSes might be supported.
It's not terribly expensive, but it adds up and if you're using the
function many times, you might want to memoize() it.
OBJECT NOTATION
The ssh_client_ip() convenience function illustrated above will suffice
for most hooks, if you want more control or diagnosing functions, use
the full object notation:
use SVN::Utils::ClientIP;
my $finder = SVN::Utils::ClientIP->new();
if( my $ip = $finder->ssh_client_ip_find() ) {
print "Found IP address: $ip\n";
} else {
print "IP address not found: ", $finder->error(), "\n";
}
LEGALESE
Copyright 2010 by Mike Schilli, all rights reserved. This program is
free software, you can redistribute it and/or modify it under the same
terms as Perl itself.
AUTHOR
2010, Mike Schilli